Did you change the setting of your second 'quest_shop' npc? The original script have been designed to call the datas of the shop through callfunc. If you didn't changed the 'Basic shop settings' just add your shop in the original quest_shop and call it with the function.

PC_NAME is hercules constant
strnpcinfo(0) should be used with addtimer instead of strnpcinfo(2)
you're searching the instance npc name of non-instance npc too
under oninstanceinit mf_loadevent is only set for non-instance map : this script is not running on instance map